Does a Metal Roofing System Need an Underlayment?
https://noon-wiki.win/index.php/Screw_Location_Recommendations_46901
We have a 1890's home with a combination Mansard style roofing as well as typical sloped roof. We are opting for a mix roof covering (Malarkey Windsor Shingles on Mansard as well as standing seam on slope) on the